selecting a current in a node in post-layout simulation

Plotting the current at "node" is meaningless. Nodes have potential, not current. You need to measure the current through something, such as the terminal of a device. So the easiest way to do this is to use Outputs->To Be Plotted... and then click on the device you want to measure the current through (which could be one of the parasitic resistors, say, but probably one of the designed devices). This will plot all the terminal currents for that device, but you could always then delete those that  you don't want.

The other convenient way of doing this might be to add a small metal resistor in the track you want to measure the current through, and then you have a convenient device that can be located through the navigator.

Regards,

Andrew.

Thanks Andrew.

What if the word 'device' in your reply context has many metal layers and if I select a single layer by going Outputs-->To Be Plotted and then taking it to the parasitic extracted view and choosing that single layer, will it plot all the current in and out by that layer ?? Also, unfortunately, I can not enable 'Save all' option in Plot all, because I have a very big schematic and I can easily go out of disk space, since I use unix servers with limited memory. I think, if I have not enabled 'Save all', it will not show the currents :( and I use Eldo; not spectre.

thanks

I believe that whenever you select a shape in the extracted view, it always picks the voltage associated with the node for that shape, not the current flowing through the resistor for that shapes (assuming you even did resistance extraction).

I don't believe you should have to save all currents in order to save a specific current; selecting the instance should save all currents for that device - and then you can delete the currents in the outputs pane that you don''t want.

Regards,

Andrew.

Thanks Andrew.
I agree with your first comment on picking a layer, which results only in the voltage of the node.

In your second comment, I have an issue. In normal simulation I pick the instance and all its current are selected. But in post layout simulation, even though I pick the instance, when I run/start the simulation, the picked outputs gets disabled for both plotting and saving and at the end I get error that no outputs are selected. So, I am left over with the option only to pick layers from the extracted-layout view for doing post-layout simulation. Plz note that, I am doing post-layout simulation in ADE L itself but just changing the environment Switch view list. How to plot current in post-layout simulation when I need to disable 'save all'- to save disk space and when I have only the option to choose something to plot from my extracted-layout view ???

Thanks

Are you selecting the instance from the extracted view or the schematic view? I would expect that you'd need to select it from the extracted view. If you select it from the schematic, then it may not know where that instance ends up, which is probably why it's disabling it. 

I was suggesting that you select an instance of a device in the extracted view for it to save all the currents for that device.

If this doesn't work, I suggest you contact customer support (referencing this discussion) so that one of the Application Engineers can take a look at it.

Regards,

Andrew.

Thanks Andrew.
Yes, I am selecting the instance from the extracted view. But please note that once the whole layout is extracted, the extracted view will not show instance-wise. Rather it will show only the layer-wise. I mean, in layout we can differential or pick an instance, whereas in extracted-layout, we can only differentiate or pick out only a layer. And because of this reason, I am unable to pick an instance in the extracted layout view :( Do you have or know a way to sort out this issue ?? I need to pick a current in the extracted-view of my layout, where there are layer-wise concept and not instance-wise.


thanks

There must be instances in your extracted view, because otherwise there would be no devices when it was netlisted. That's how extracted views work!

I don't know what version you're using, or even which extraction tool you're using, but if it's a recent enough version you should be able to use Window->Assistants->Navigator and select instances through that too.

Anyway, I've probably reached the limit of the help I can offer without seeing your setup, so I think if this doesn't help, you really will have to go via customer support.

Regards,

Andrew.